The increased prevalence of many of the health problems of African American women has been linked to the high prevalence of obesity. Of great concern, the prevalence of obesity has been increasing among African American women with a similar pattern in African American girls. Since weight reduction weight is difficult to achieve in adulthood, there is an urgent need for prevention approaches geared towards children. This proposal describes a two-phase plan to develop and evaluate a community-based intervention that promotes healthy dietary practices and increased physical activity among at risk or overweight 8-10 year-old African American girls living in low- income neighborhoods in the Twin Cities of Minneapolis and St Paul, Minnesota. A randomized clinical trial design will be used with 300 African American girls; 150 will be individually randomized to the intervention group and 150 to the control group. The intervention program will take place after school, two afternoons a week in neighborhood community centers and will be based on social cognitive theory, incorporating a youth development, resiliency-based approach. Community involvement through the establishment of a Community Advisory Council will provide input into all aspects of the study. The intervention focuses on activities designed to model and teach skills to prevent obesity through regular physical activity and healthy eating and a family component designed to reinforce and support these behaviors. An effective and innovative culturally- appropriate intervention will be developed through formative assessment with girls, parents, community leaders and youth workers in the targeted communities. In Phase I, a 12-week pilot-test will be conducted with 50 girls; 25 randomized to the intervention and 25 to the control group. In Phase II, the two-year intervention will be conducted in five community centers, twice a week for 11 months. Main outcome measures will be body mass index (BMI) and percent body fat (percent BF). The major hypothesis is that at the end of the full-scale study, girls in the intervention group, relative to girls in the control group, will have significantly lower BMI and percent BF after adjustment for baseline values. Secondary outcomes include physical activity level, total energy intake, percent intake from dietary fat, child and parent psychosocial factors related to diet and physical activity, blood cholesterol and blood pressure. Process measures will assess program implementation including measures of exposure, participation, compliance, receptivity, and fidelity of implementation.